He is an Iridonian Zabrak, a sub-species of people from the planet Iridonia. He is notable for his red skin, prolific Sith tattoos, facial horns, and his red-yellow eyes. He wields a double-bladed red lightsaber, the second blade of which can be left unignited in a battle with a single opponent or extended to form a saberstaff in battle with large numbers of enemies. He also utilises probe droids to scout for his enemies, a self-constructed speeder bike named Bloodfin to catch up to his enemies, and a Sith Infiltator ship named Scimitar to travel between star systems.
He appears only in The Phantom Menace and the second Clone Wars cartoon. He says very little in the first appearance; in the second, he hardly ever shuts up.
In The Phantom Menace, he attacks Amidala's group on Tatooine. He duels Qui-Gin Jinn and is winning the fight until Qui-Gon escapes by grabbing onto the boarding ramp of Amidala's ship as it flies overhead. He attacks again during the battle to free Naboo. He duels both Qui-Gon and Obi-Wan, holding them off with the aid of his double-bladed lightsaber. He manages to separate them with the aid of timed forcefields, and kills Qui-Gon as Obi-Wan watches helplessly. He then duels Obi-Wan, who cuts his lightsaber in half, and shoves the Padawan down a pit. However, he is killed when Obi-Wan calms himself and leaps out of the pit, Force-guides Qui-Gon's lightsaber into his hand, and cuts Darth Maul in half.
His body is later reconstructed by a group of renegade Prophets of the Dark Side and set against Darth Vader, who destroys him. Annoyingly, Leland Chee has declared the incident canon, though all other resurrections (hopefully) aren't.
An interesting aspect of Darth Maul's character is his patience. According to some sourcebooks, he had no intention of ever turning on Darth Sidious, and would have instead simply waited for him to die of natural causes.